The concept of a circular runway for airports may revolutionize air travel, reducing flight times, saving fuel costs and promoting airport efficiency.
The architecture of airport runways has remained mostly unaltered ever since the creation of aeroplanes. The EU-funded project ‘The endless runway’ conceptualized a comprehensive design for a runway, based on a circular track that is encircled around the airport. Such a runway may allow planes to take-off in any direction and land from any direction, lessening trajectories, avoiding runway crossings and smoothening landings in any weather.
Initially, the project team proposed a circular runway featuring a radius of 1.5 to 2.5 km, which allows modifications to active airports more readily. Such a runway should also be 400 m wide, to strike a balance between restricting centrifugal forces and safety considerations. Amazingly, many aircraft can operate such a 10 km runway simultaneously.
To achieve its goals, the project evaluated three operational models. The first was designed for low-wind scenarios where any part of the circle can be utilized in any direction. The second was for a high-wind scenario identical to an airport with two parallel runways. The third model considered changing winds, involving an aircraft sequence that gradually moves with the wind direction.
With these scenarios as a concept, the project team discovered that the idea could reduce take-off and landing tracks overall by 10 % in comparison to straight runways. The model strengthens more sustainable operations that don’t always depend on the wind, with total land use being smaller than that of conventional airports. The construction budget will be 10–60 % higher. The concept offers benefits in terms of shorter trajectories, less taxi time and endless capacity, ideal for increasing air capacity in the world.